Telephone system



Jan. 8, 1935.

L. J. BOWNE TELEPHONE SYSTEM Filed Jan. 26, 1933 3 Sheets-Sheet 1INVENTOR y L.J. BOW/VE I ATTORNEY Jan. 8, 1935. J. BOWNE 1,987,430

TELEPHONE SYSTEM Filed Jan. 26, 1933 3 Sheets-Sheet 3 FIG. 4

INVENTOR L. J. BOWNE ATTORNEY Patented Jan. 8 1935 minim O FFI C -E987330 ;='DELERHONE SYSTEM Langfofd iLBownefHpwarflFBach, 'N. 'Y.,'assi'gn'or to 3611 Telephone 'LQbOl'flfiOliQS, =Incorporated,NewYorkfiNY a-=corporation df NewYork Applicatibn Qlanuary '26, I933,Sesial No. 653,592

Thissinventiomnelatesdzo telephunezsystemseand zpasticularly tn aarrangements :for ip'reven'ting :"aenustic :shodks 7dr high :pdtentialsignals from penetrating to roperatorfs :and subscribeifs tapapa'ratus.

rjAinTObjGCt of $thfiI1V8IifiOnIiS it'o simplifiy teleqihone Fsystems in(which 'ter'minal apparatus is ito "be prnteeted against ia'cbustic:sho'ck tcaused my high petentialssignals virnmmxte'mal squrees '01ithat fare itransmittedmver atelephone alines for-otherrsignalingipurp'dsesAfor examplai'whenisuch ttelephone lines [areused win trailway train dispatching systems. a I :Heretdfore, *systemsfliave :been zprovided which itleph'on'e :lines shave :b'een aequippedwith rshecksabsorbing meansito'ip'rotedt inerminalsequinsment :firomzex'ces'sive :voltages from external .sources and ;yet permit signalingicu'rrentstof the :usual telerihone-1'sigm11voltages to be transemittedever :t'he "line to the tterminal :rapp'aratus.

In such systems, wacuum ftube :rcircuits were Eb-ridged :across theslime :in combinati'on with m -filtervsarrangement whereby whe'n *rtheline was exposed ito e'xce's'sive :V01ta'geS,-.Suh voltages nperated thevacuum tube circuit anil shott-cirsuited the' telephonei lineandwereithus prevented Efrem affecting the terminal apparatusivhile iwhen'ringing'signals of ordinar-y lower telepho'n'e v01t- "age were a'ppliedto' lthe line, suh signals We're :p'revented by filters from ope'ratingthe vacuum tube circuit aanil thereby' pel mitmd to :be Mansmitted tothe terminalapparatus, V

' On'e feature "of lth'e "present inventidnproiiides shoe-k'p1otectiv'eme'ans nor the -te'rmina'lta'pparaxtus against signals o'fhi'gh b otential br 'other ex- "c'essiv e vol tage's 'from externalsources by s-hort- :circuiting such signals, While -'or'clinary ringingsignals 'having voltages' usual in telephone sircuits are permitted 'tobe repeated past -said pro"- testive -'means as usual ringing si nals tothe teriminal apparatus.

.mnoth'er feature (of this invention .pmvides means whereby the usualringing :s'ignals may :he rtran'smitt'ed afrom the terminal apparatusout over the 'line 'by repeating 'ipa'st I'the sh'oc'kapfo- :tecting:mean's.

.vAnother :feature of ithe invention lp'rovides means 'vmereby highzpute'ntial signals :may be transmitted over ith'e ztelephone line atthe call originating end or at an y paint "along the line and. whe'rebysuch signals are prevented froin "passing through its the terminalapparatus at the call :ori'gi'nating :endib'f the telephone line.

Another Keeature :o-f the invention 'mfovide's means :a tithe receiving'en'c'l ci'f a ti'alelihon'e lin'e ol att-any point :along the line fortranslating such lhighspnteritialsignalssintoilowzpotential ordinarywinging-signals to bereeeivedhy theTtern'iiI1'al =ap"- vparatus'at'theereceiving end. of said time or at terminal :apparatus at any pointalong the line, :dep'ending :onathe code .represented by the trans-:m'itted isig'nals :ian'd Ito protect said terminal ap {paratusifrumreceiving shocks causedby sai'd high potential signals.

.a xnot'h'er feature of thisinvention proviiies means whereby .=anaudib'le tone signal -is pern'iiitte'd to; pass back :'over the "line asan answerthafekisignal io'f the signal received iby ithe'seleetedsteirminating apparatus.

Another feature resides in the :lprov'i'sion o'f imeans whereby:or'din'ary low potential ringing signals may The transmitted over thetelephone iline from "a call -originating=end past the shockabsorbingsmeans and whereby si'gnals of the same .chara'eteris ticsimaybe received at said call origiinating ehdfiincoming-over the line and.'refiea'ted ipa'st th'e :shock p'rotecting means :at said end.

Referring now no =the-drawings, Fig. '1 shows (inagenerakdiagrammatic-form theinvention applied to a train despatch-ingsystem using teleqihon'e lines; I

' Fig. 2 shows the terminating telephone equip: :lnent at the icallingend of a telephone line and Fig. 3 :shows the terminating telephoneeqiiipment- 'a't the called-end ofatele ihoneline -u'sed I for .ltra'indesp'atching and embotlying certain features of thi's invent'ion; and

Mg. 4 shows the itermina'l equipment at the warning and e'alleden'dsfo'f a fihan'tdm telephone mm, the "side-circuits of which may beused for train desp'atclfing embodying certain features =0'f thisinvention;

Referring now particularly "to Fig. 1, the vari- 011s -features havebeenapplied as stated to a train iie'sDatching-syst'em using telephone=1ines forth'e stations; 'The despatchers -1ine is provided at the e'aliing statiGn *A'W'i'th the train desnatc'hersteleshone set 3 and theusual "train "despa't'ching 'ca11- manner sm i-r'epre'sented-indiagrammaticfor'm a s-employed the train despateher for selecting-*waystations. Such systems usually'comprise .vention to various types ofsystems. features of this invention. are embodied in the terminalapparatus at stations .A and B at 18,

provided at 10 for calling the way stations 11, 12 and 13 or theterminatingapparatus at the called station E as shown at 15. The waystatiorr apparatus 11, 12 and 13 maybethe same as way station apparatus5, 6 or 7. A terminating station 16, similar to station 15, may also beprovided 7 for the establishing of telephone connections between stationA and this'station 16, or between station B and this station 16. Thedespatchers,

line 1 and the message line 2 may be connected and serve as sidecircuits of a phantom:line circuit terminating at stations-A and B interminal apparatuslB and 19, respectively. This arrangement is merelyshown to illustrate the possibilities of the application of the featuresof this in- The various 10, 19, and 16.

When the message line 2 is used for telephone purposes, the terminalapparatus has to be protected against acoustic shocks caused by the.train despatching signals that may aifect this line either by thesending of the calling signal from station A to call anyof the waystations 11, 12, 13 or 15, or by disturbing influences thatmay bevcaused when line 1 is used for train despatching. purposes that may betransmitted or effective on line 2 possibly by some disorder due to theconnection of the phantom line or, anyother disturbances.

Likewise, the terminal apparatus at 15 and 16 must be arranged toprevent train despatching signals of the same character from affectingthe terminal apparatus. The terminal apparatus at 15 is also arranged sothat it may be calledby train despatching signals transmitted fromstation A'and equipment-10 and these signals are translated intoordinary ringing signals for the calling of the terminal apparatus atthis end. Shock, absorbing equipment must also be provided at 15 for theprevention of traindespatching signals alfecting this terminalapparatus. The terminating station 16 is equipped with these protectivedevices and translating devices the same as station 15. In regard toterminal apparatus Is and 19, these are arranged for sending andtransmitting ordinary ringing signals over the side circuits and ifeither of the side circuits are used for train despatchingsignals theseterminal apparatus have to be similarly protected from acoustic shockfrom such signals.

1 Description will now be made in connection with Figs. 2 to 4 of thevarious features of this invention relating to the shock protectingdevices and the signaling means-provided at the terminal apparatus.Figs. 2 and 3 show the terminal apparatus of the message line 2 atstations A and B, respectively. Fig. 3 serves toillustrate boththeequipments at 15 and 16 of Fig. 1, while Fig. 2 illustrates theequipment 10 of Fig. 1 Fig. 4 shows the terminal apparatus at 18 and 19of the phantom circuit of Fig. 1. To illustrate the features ofthisinvention, a description will be made first .of a call from thecalling station A at 10 over line 2 to call the terminal apparatus 15 atstation B and the various functions caused thereby, such as thetranslation of the train despatching signals into ordinary ringingsignals at the terminal apparatus 15 and the ring-back signal causedthereby to be received at the calling station A by the terminalapparatus of line 2. Description will also be made of signaling betweenterminal apparatus at stations 15 and 16 after said stations have beenconnected up for telephone purposes. Finally, a description will be madeof signaling over the phantom circuit between terminal apparatus 18 and19. One of these terminal apparatus is represented in Fig. 4 and thedescription will be made in connection with this figure. v

If the call is to be made from the calling station A at 10 over line 2,the calling operator insert's plug int'o'jack 31 and thereby causes theoperation of relay 33 over an obvious circuit closed by the jackcontacts. This relay, in operating,

.'-provides a connection from ground for the middle spring of .the traindespatching key 34 by means 'of which the operator may signal out overthe next line.

The operator may now ring the desired station or terminal apparatus atstation B by operating the key 34 to send the desired code.

'Althoughjonly one key has been shown, it should .be understood that in'ordinary equipment of this type, a-number of keys may be supplied, eachone having 'a difierent code. The operation of this keyis such that theconnections. between the contacts are established on the return of thekey to normal when a circuit is completed for the operation of relay35.from battery through the winding of this relayand lower contacts ofkey 34 to ground at relay 33. Relay 35 is slow in releasing so that itwill remain operated while the code pulses are being sent. With relay35, operated, a circuit :is closed for relays 36 and 37 over obviousvcircuits. .These relays operate to close the circuit from the-armatureand front contact of relay 35 through .the lower armature and frontcontact of relay 36 and upperarmature and front contact of relay .35 tothe lead 37 which terminates in the usual special signal apparatusmerely .shown in diagrammatic form as a box 38. It should be notedthat-a lead 39 is connected to 38 from the ground at the armature andfront contact of relay 33 and key 34.during pulsing. These groundconnectionson leads 37 and 39 cause the selector apparatus to connecthigh potential signals to leads 40 .in accordance with the codeselection on'key 34 controlled through the opening and closingof theconnection for lead 39 through the two upper contacts. of the key.Referring nowto the operation of relays 36 and 3'7, these relaysdisconnect the repeating coil from line 2 and connect the repeating coil4-6 to the tip and ring conductors in series with the right-hand windingof repeating coil 45. Impulses over leads 40 are transmitted through theleft-hand winding of repeating coil 46 to the. right-hand winding ofthis coil and line 2., .Theprotecting means for preventing these highpotential low frequency signals from effecting the operators telephoneset 49 during the signaling-period comprises a repeating'coil 50 havingits left-hand windings bridged across the tip: and ring conductorstowards the operators telephone set, while the right-hand windings areconnected in parallel to the-elements of the neon glow .tube 51. Theimpedance .of the repeating coil 50,-which-isnormally high to voicefrequencies, dropsrapidly due to the resistance of the neonlamp breakingdown under the high voltage signals imposed on it from the repeatingcoil 50. When the high voltage signal condition is removed, theresistance of the neon tube and impedance of repeating coil return tonormal. Because of the rapid functioning of the neon tube 51,practically none of these signaling po-- tentials are impressed upon therepeating coil 45 and electric or acoustic shocks are thereforeprevented from affecting the operator's telephone set 49. The repeatingcoil 45 is also provided to insulate the operators telephone equipmentof the terminal apparatus from normal line currents which may beconnected to it by means of the signals transmitted over the line 2 whenused as a side circuit for phantom connections illustrated in Fig. l.

The high potential low frequency code signals incoming at station 13 tothe terminal apparatus at 15 will be received in the usual traindespatching signal apparatus shown by means of a box 100. This apparatusis so arranged that the code causes a ground to be applied to the lead101. Relay 102 is thereby operated over an obvious circuit from battery.This relay connects ringing current through the repeating coil 103, theprimary circuit of which is closed from the ringing source 104 throughthe upper inner armature and front contact of relay 102, while thesecondary is connected to the tip and ring conductors at the upper outerand lower outer armatures and front contacts of relay 102. Ringingcurrent is thereby transmitted to operate relay 106 through repeatingcoil 105. Relay 106 closes a circuit for lighting lamp 107. It should benoted that in this case the train despatching signals do not affect theterminal apparatus as the tip and ring conductors are open at contactsof relay 110. Relay 102 releases at the end of the signaling period asthe ground connection on lead 101 is removed when the train despatchingsignaling apparatus is restored to normal. Audible ringing tone is sentback from this circuit via condensers 111, 112, 113 and 114. Thisaudible answer-back signal is sent back over line 2 to the sendingstation at A through repeating coil 46, condensers 56 and 57, outerupper armature and front contact of relay 37 and outer lower armatureand front contact of relay 36, repeating coil 45, repeating coil 58,jack 31, plug 30, to the operators telephone set 49. The high potentialsignaling protecting means 50 and 51 do not affect these answer-backsignals to any appreciable extent.

To answer this call, the operator will, on seeing the lamp 107 lighted,insert a plug 115 in the jack 116 and thereby close the circuit throughthe sleeve terminals for the operation of relay 110.

This relay nowconnects the tip and ring conductors through for talking.In case any disturbing high voltage signals are received over the linewhile this connection exists, such as, for example, might happen in caseof signaling from a Way station by train despatching signals, theoperators telephone set 118 if connected at this time will be protectedfrom acoustic shocks by the protecting means comprising a repeating coil120 having its right-hand windings bridged across the tip and ringconductors and its left-hand windings connected to the neon tube 122.This arrangement of repeating coil 120 and tube 122 operates in the samemanner as described in connection with the terminal apparatus at stationA, namely, to short-circuit the high potential low frequency codesignals.

The terminal apparatus 15 is provided for receiving and sending lowpotential ringing signals. Such signals will be received or transmittedunder circumstances such as, for example, when the terminal apparatus 15has been called and connected up to an operator's position and where theterminal apparatus 16, for example, has also been called and connectedup to an operators position. If, under these circumstances, for example,the operator at 118 desires to call the operator connected to theterminal apparatus at 16, he will operate his usual ringing key 123 andthereby cause the operation of the ringing relay 124. This relay, inturn, closes a circuit for the operation of ringing relay 125 at itsinner righthand armature and front contact and short-circuits the lineat its right-hand armature and front contact to prevent relay 131 fromoperating falsely. Relay 125, in operating, closes an obvious circuitfor the operation of relay 126. This relay opens the circuit for relay110 which releases and connects the tip and ring conductors of line 2through the contacts of relay 126, to the ringing current source 104through the windings of repeating coil 103. Relay 126 also closes acircuit for the operation of relay 129. When the ringing current fromthe operators cord ceases, relays 124, 125 and 126 are released andrelay 110 reoperates. At this time a surge of current from the line maycause relay 131 to operate falsely due to the connection established bythe reoperation of relay 110. Relay 129 which is slow in releasing willhold over between the time of the release of relay 126 and the operationof relay 131 if it should operate due to such line circuit, so thatrelay 129 will be held'operated from the contacts of relay 131 untilline current surges are dissipated. Relay 129 opens the circuit from thecontact of relay 131 to the winding of relay 102, thus preventing afalse ringing signal being sent back to the operator.

If the operator at 118 is to be called by a reringing signal from, forexample, the terminal equipment 16, the signal current is transmittedover the line and is. received by the operator at 118. This signalcauses the operation of relay 131 and the operation of this relay closesan obvious circuit for the operation of relay 102 which connects ringingcurrent to the operator at 118 in the same manner as when this relayoperated due to a train despatching signal as hereinbefore described.

Referring now to Fig. 4, description will be made of this circuit whenused as the terminating apparatus at 18, for example. In this case ifthe operator at 200 inserts her plug 201 into the jack 203 and operatesher ringing key 204, relay 205 operates. This latter relayshort-circuits the tip and ring conductors outgoing over the phantomcircuit by its outer left-hand armature and front contact and closes acircuit for the operation of relay 207. Relay 207 closes an obviouscircuit for the operation of relay 208 to connect the right-hand windingof the repeating coil 209 to the tip and ring conductors outgoing overthe phantom circuit and to connect the left-hand Winding of therepeating coil to the ringing current source at 210. Ringing currentwill now be transmitted out over the phantom circuit to call theterminal apparatus at 19. Relay 208, in operating, also closes anobvious circuit for relay 211 for the same purpose as relay 129 wasoperated in terminal apparatus 15, namely, to prevent surges from theline from afiecting the operators set due to the possible falseoperation of relay 212. If this terminal apparatus is called over thephantom'circuit, relay 212 is operated thereby causing the operation ofrelay 214 which relay, in turn, closes connections for the transmissionof ringing current from source 210 and its upper and lower outerarmatures, and front contacts through repeating coils 209 and 216 forthe operation of ringing relay 217 which, in operating, lights lamp 218.

This terminal apparatus is protected from the high voltage low frequencysignals incoming over the phantom circuit due to train despatchingsignals over either the message line or the despatching line by the sametype of means as the terminal apparatus at 10 or 15, namely, repeatingcoil 220 and neon glow lamp 221., It is seen by the location of therepeating coils across the tip and ring conductors in this circuit thatit is necessary to relay both incoming and outgoing ringing signals pastthe equipment.

What is claimed is:

1. In a signaling system, an exchange, a line connected to saidexchange, means for transmitting high potential low frequency currentsignals out over said line, protective means for preventing said signalsfrom passing towards the exchange, means for connecting said protectivemeans in the line during the transmission of said signals, and means forreceiving low potential high frequency signals at said exchange incomingover said linewhile signaling with high potential low frequency current.

2. In a signaling system, an exchange, a line incoming to said exchange,a high potential current source, signaling means including a key forproducing low frequency alternating current signals from said highpotential current source, a repeating coil for coupling said signalingmeans to said line for the transmission of high potential low frequencyalternating current signals out over said line when said key isoperated, protective means including a repeating coil and a neon glowtube for preventing said high potential low frequency alternatingcurrent signal from passing towards the exchange, and means includingsaid first mentioned coupling repeating coil for receiving low potentialhigh frequency signals at said exchange incomingover said line whilesignaling with the high potential low frequency alternating current.

3. In a telephone system, an operators telephone set, a line, means forconnectingsaid telephone set to said line, means for transmitting highpotential low frequency alternating current signals out over said line,means for preventing said signals from passing to said telephone set,means for connecting said last mentioned means in said line during thetransmission of said signals, and means for transmitting low potentialhigh frequency signals to said telephone .set received over said lineWhile high potential low frequency alternating current signals aretransmitted out over said line.

4. In a telephone system, an operators telee phone set, a line, meansfor connecting said line to said operators telephone set, meansoperative in response to the establishing of said connection fortransmitting high potential low frequency alternating current signalsout over said line and for preventing said signals from acousticallyaffecting said telephone set, and means for acoustically detecting insaid telephoneset low potential high frequency signals received oversaid line while signaling with said high potential low frequencyalternating current signals.

, 5. Inasignalingsystem,aline, means responsive to high potential lowfrequency signals received from one end of the line for converting saidsignals into low potential signals for transmission out over both endsof the line, means for repeating low potential signals over said linefrom either end thereof, and means for preventing high potential signalsincoming from said one end of the line from penetrating to the other endof the line.

6. A transmission line, a protective device associated with said linefor short-circuiting high potential signals incoming over said line, arelay on each side of said protective device responsive to low potentialsignals on said line, and means responsive to the operation of eitherrelay for transmitting low potential signals out over the opposite endof the line past said protective device.

'7. In a signaling system, an exchange, a line incoming to saidexchange, means responsive to high potential low frequency alternatingcurrent signals received over the line for converting said signals intolow potential ringing frequency signals fortransmission to the exchange,means for signaling out over the line with low potential ringingfrequency signals in response to the reception of said high potentiallow frequency alternating current signals incoming over the line, meansfor repeating low potential ringing frequency signals over said linefrom either end thereof, and means for preventing high potential lowfrequency signals incoming over the line from passing over said linetowards the exchange.

8. In a telephone system, an operators position including an operatorstelephone set, a line incoming to said position, means associated withsaid line responsive to high potential low frequency alternating currentsignals received over the line for transmitting low potential ringingfrequency signals to said position, means for repeating said lowpotential ringing frequency signals out over the line, means forrepeating low potential ringing frequency signals incoming over saidline to said position, means for repeating low potential ringingfrequency signals from said position out over said line, and means forpreventing incoming high potential low frequency signals incoming overthe line from causing acoustic shocks in said telephone set.

9. In a telephone system, a first and a second exchange, an operatorsposition including a telephone set at said second exchange, a lineinterconnecting said exchanges, means for connecting said line to saidposition, means at said first exchange for signaling over said line withhigh potentialsignals, means at said second exchange for translatingsaid high potential signals into low potential signals for transmissionto said position, an acoustic shock absorbing means at said secondexchange for preventing transmitted high potential signals frompenetrating to said position to affect the operators telephone set, andmeans for repeating low potential signals received over said line ineither direction past said acoustic shock absorbing means.

10'. In a telephone system, an operators cord circuit including anoperators telephone set, a line. means for connecting said line to saidcord circuit, acoustic shock absorbing means in said line for preventinghigh potential low frequency signals incoming over the line fromaffecting said operators telephone set, means responsive to highpotential low frequency alternating current signals received over theline for converting said signals into low potential ringing frequencysignals for transmission past said acoustic shock absorbing means tosaid operators cord circuit, and means for repeating low potentialringing frequency signals past said acoustic shock absorbing means whensaid signals are received from the line to the operators cord circuit orwhen they are received from said operators cord circuit to the line.

11. In a signaling system, an exchange, a line incoming to saidexchange, a high potential low frequency alternating current signalreceiving means associated with said line, an acoustic shock absorbingmeans associated with said line, means for converting high potential lowfrequency signals received by said means into low potential ringingsignals and for transmitting said low potential ringing signals pastsaid acoustic shock absorbing means towards said exchange, and meansresponsive to said low potential ringing signal for transmitting audibletone over said line past said acoustic shock absorbing means out oversaid line away from said exchange.

12. A transmission line, a protective device associated therewith forshort-circuiting high potential signals incoming over said line, a relayassociated with said line responsive to low potential alternatingcurrent signals of a higher frequency, and means responsive to theoperation of said relay for transmitting signals over said line pastsaid protective device.

13. In a signaling system, a calling station, a called station, a lineconnecting said stations, high potential current code signaltransmitting means at said calling station for transmitting code signalsover the line to call any one of said called stations, means at thecalling station for preventing said code signal from passing back beyondsaid calling station, means at each of said called stations forresponding to a particular code signal transmitted over the line and fortranslating said code signal into a low potential ringing signal fortransmission beyond said called station and for transmission back overthe line towards the calling station, means at the called stations forpreventing any code signals transmitted over the line from passingbeyond the called stations, means at the calling station fortransmitting a low potential signal received over the line from a calledstation back beyond said calling station, means at a called stationoperative if said called station has not been previously called by acode signal for transmitting low potential signals back over said line,and means at any called station operative if previously called by a codesignal for transmitting low potential signals incoming over the linebeyond said called station.

14. In a signaling system, a line, means for transmitting low potentialringing signals to both ends of said line, means for repeating said lowpotential ringing signals over said line incoming from either end, meansfor transmitting high potential signals from one end of said line, meansfor preventing said high potential signals from passing through to theother end of said line, and means responsive to said high potentialsignals for transmitting low potential signals to said other end of saidline.

LANGFORD J. BOWNE.

